1. Field of the Invention
This invention relates to an engine cooler to be used for cooling the engine of automobiles.
2. Prior Art
Conventional engine radiators for automobiles are described, for example, in Japanese Utility Model Publication No. 42181/1985 and in Utility Model Laid-open Publication No. 1918/1985. The device described in Utility Model Publication No. 42181/1985 is equipped with an upper tank 41 including an inlet pipe and a lower tank 42 including an outlet pipe as illustrated in FIG. 11, said both tanks 41 and 42 being connected with a plurality of water tubes 43, radiation fins being disposed between said tubes 43, and cooling fan 44 being installed facing the front of the vehicle. In the figure, numeral 45 represents the radiator and numeral 50 the engine. If this radiator 45 is mounted on an automobile as shown in FIG. 11, the shape of the body line of the automobile will be restricted by the height of the radiator 45 to be installed in the front of the engine 50, posing problems in reducing the CD value (coefficient of air resistance) and resulting in adverse effects to the vehicle performance, fuel costs and others.
The required heat radiating area of a radiator is determined in proportion to the amount of heat generated by the engine so that an attempt to decrease the height will result in increased size in the horizontal direction. This made it difficult to cool the engine effectively with a cooling fan.
To resolve this problem, it may be possible to dispose the radiator aslant the traveling direction of the vehicle or installing a plurality of radiators. In this case, however, it is difficult to effectively utilize the speed wind caused by the running vehicle. The reason is that with this arrangement, the shroud and cooling fan are installed in the direction of speed wind and they give resistance to the speed wind.
The device described in the aforementioned Utility Model Laid-open Publication No. 1918/1985 is a one in which radiator 171 and cooler condenser 172 are disposed facing the traveling direction of the vehicle and which comprises cooling fan 173 rotated with the drive force of engine 160 to blow cold air, shroud 174 to guide the cold air, and motor fan 175 to cool cooler condenser 172, as shown in FIG. 12.
In the aforementioned device, since the radiator 171 and cooler condenser 172 are installed in the longitudinal direction to blow cold air, the pressure rises between the radiator 171 and the cooler condenser 172 due to stagnant cold air, thereby causing back flow or spiral vortex of the cold air to deteriorate the cooling efficiency noticeably. Also the motor fan 175, cooling fan 173 and shroud 174 give resistance to the speed wind also when the vehicle is running, resulting in extremely deteriorated cooling efficiency due to the speed wind. Thus it has been a problem in that the capacity of the cooling fan 173 and radiator 171 had to be increased more than necessary.
To resolve the aforementioned problem, in the device shown in Provisional Utility Model Publication No. 155723 of 1985, a flutter is provided to the shroud to reduce the resistance of the speed wind due to the movement of the fan body, but it is difficult to eliminate the fan body and the reduction of resistance due to the movement of the flutter and fan is restricted by the structure of the shroud and the layout of the engine. Therefore, the cooling efficiency cannot be fully exhibited and the mechanism is complex and costly.